The short version of heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-11-28. Anything still debated is marked as such rather than presented as settled.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analogue of the ACTH(4-10) fragment |
| Amino acid sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Single-letter form MEHFPGP |
| Molecular formula | C37H51N9O10S | Free peptide, nominal mass near 814 Da |
| First registration | 1994, Russia | Nasal formulation for neurological indications |
| Typical purity grade | 95% or higher by HPLC | Research material; higher grades used as reference standards |
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
=== Geometry === The majority of β-strands are arranged adjacent to other strands and form an extensive hydrogen bond network with their neighbors in which the N−H groups in the backbone of one strand establish hydrogen bonds with the C=O groups in the backbone of the adjacent strands. In the fully extended β-strand, successive side chains point straight up and straight down in an alternating pattern. Adjacent β-strands in a β-sheet are aligned so that their Cα atoms are adjacent and their side chains point in the same direction. The "pleated" appearance of β-strands arises from tetrahedral chemical bonding at the Cα atom; for example, if a side chain points straight up, then the bonds to the C′ must point slightly downwards, since its bond angle is approximately 109.5°. The pleating causes the distance between Cαi and Cαi + 2 to be approximately 6 Å (0.60 nm), rather than the 7.6 Å (0.76 nm) expected from two fully extended trans peptides. The "sideways" distance between adjacent Cα atoms in hydrogen-bonded β-strands is roughly 5 Å (0.50 nm).
In the early 17th century, the majority of the labour in Barbados was provided by European indentured servants, mainly English, Irish and Scottish, with African and native American slaves providing little of the workforce. The introduction of sugar cane in 1640 completely transformed society and the economy. Barbados eventually had one of the world's largest sugar industries. The workable sugar plantation required a large investment and a great deal of heavy labour. At first, Dutch traders supplied the equipment, financing, and African slaves, in addition to transporting most of the sugar to Europe. In 1644, the population of Barbados was estimated at 30,000, of which about 800 were of African descent, with the remainder mainly of English descent. By 1700, there were 15,000 free whites and 50,000 enslaved Africans. In Jamaica, although the African slave population in the 1670s and 1680s never exceeded 10,000, by 1800 it had increased to over 300,000. The increased implementation of slave codes or black codes, which created differential treatment between Africans and the white workers and ruling planter class. In response to these codes, several slave rebellions were attempted or planned during this time, but none succeeded.
These merged in 1962 creating the ULS. In 1979 the society had 11,000 members in 11 states and Canada. Headquarters in Ligonier, Pennsylvania. Zivena Beneficial Society - Founded in 1891. Headquartered in Ligonier, Pennsylvania, since at least the late 1970s, but in the early 1920s headquartered in Braddock, Pennsylvania. Had 5,611 at the end of 1918. 7,277 members in 1927, 4,357 in 1965, and 2,500 in 1977. The national convention met quadrennially. Licensed to sell insurance in Illinois, New York, Ohio, and Pennsylvania. Sponsored scholarships, gave aid to aged and handicapped members, and donated to civic and charitable groups. Merged into Croatian Fraternal Union in 1995.
Flucloxacillin is a narrow-spectrum antibiotic belonging to the penicillin group of antibiotics. It works by breaking down the bacterial cell wall. Like other β-lactam antibiotics, flucloxacillin acts by inhibiting the synthesis of bacterial cell walls. It inhibits cross-linkage between the linear peptidoglycan polymer chains that make up a major component of the cell wall of Gram-positive bacteria. Flucloxacillin is more acid-stable than many other penicillins and can be given orally, in addition to parenteral routes. However, like methicillin, it is less potent than benzylpenicillin against non-β-lactamase-producing Gram-positive bacteria. Flucloxacillin has similar pharmacokinetics, antibacterial activity, and indications to dicloxacillin, and the two agents are considered interchangeable. It is reported to have higher, though rare, incidence of severe hepatic adverse effects than dicloxacillin, but a lower incidence of renal adverse effects.
(1) Most often, 5'-DMT group is removed at the end of the oligonucleotide chain assembly. The oligonucleotides are then released from the solid phase and deprotected (base and phosphate) by treatment with aqueous ammonium hydroxide, aqueous methylamine, their mixtures, gaseous ammonia or methylamine or, less commonly, solutions of other primary amines or alkalies at ambient or elevated temperature. This removes all remaining protection groups from 2'-deoxyoligonucleotides, resulting in a reaction mixture containing the desired product. If the oligonucleotide contains any 2'-O-protected ribonucleotide residues, the deprotection protocol includes the second step where the 2'-O-protecting silyl groups are removed by treatment with fluoride ion by various methods. The fully deprotected product is used as is, or the desired oligonucleotide can be purified by a number of methods. Most commonly, the crude product is desalted using ethanol precipitation, size exclusion chromatography, or reverse-phase HPLC. To eliminate unwanted truncation products, the oligonucleotides can be purified via polyacrylamide gel electrophoresis or anion-exchange HPLC followed by desalting. (2) The second approach is only used when the intended method of purification is reverse-phase HPLC. In this case, the 5'-terminal DMT group that serves as a hydrophobic handle for purification is kept on at the end of the synthesis. The oligonucleotide is deprotected under basic conditions as described above and, upon evaporation, is purified by reverse-phase HPLC.
Sources: en.wikipedia.org
=== Pharmacokinetics === Literature reviews have stated that fluvoxamine is metabolized primarily by CYP2D6 and to a minor extent by CYP1A2. However, CYP2D6 poor metabolizers do not have considerably higher fluvoxamine levels than extensive metabolizers. Fluvoxamine inhibits oxidative drug metabolising enzymes (particularly CYP1A2, and less potently CYP3A4 and CYP2D6) The mean plasma half-life of fluvoxamine after multiple oral doses of 100 mg/day in healthy, young volunteers was 13.6-15.6 hours. In the elderly, however the half life ranged from 17.4 to 25.9. Steady-state plasma fluvoxamine concentrations were 2-3 fold higher in children than in adolescents.
=== Pharmacokinetics === Temozolomide is quickly and almost completely absorbed from the gut, and readily penetrates the blood–brain barrier; the concentration in the cerebrospinal fluid is 30% of the concentration in the blood plasma. Intake with food decreases maximal plasma concentrations by 33% and the area under the curve by 9%. Only 15% (10–20%) of the substance are bound to blood plasma proteins. Temozolomide is a prodrug; at physiological pH, it is spontaneously hydrolyzed to 5-(3-methyl-triazen-1-yl)imidazole-4-carboxamide (MTIC), which undergoes further hydrolysis to methyldiazonium, likely the active methylating agent, and 5-aminoimidazole-4-carboxamide (AIC). Other metabolites include temozolomide acid and unidentified hydrophilic substances. Plasma half-life is 1.8 hours. The substance and its metabolites are mainly excreted via the urine.
=== AI Opportunities Action Plan (2025) === In January 2025, Prime Minister Keir Starmer's Labour government published the AI Opportunities Action Plan, an independent report commissioned from technology entrepreneur Matt Clifford and presented to Parliament by the Secretary of State for Science, Innovation and Technology. The plan acknowledged that while the UK is the third-largest AI market globally, it "risks falling behind the advances in Artificial Intelligence made in the USA and China". The plan is structured around three strategic goals:
Diagnostic Measurement Tools – Clinical psychologists are able to diagnose psychological disorders and related disorders found in the DSM-5 and ICD-10. Many assessment tests have been developed to complement the clinicians clinical observation and other assessment activities. Some of these include the SCID-IV, the MINI, as well as some specific to certain psychological disorders such as the CAPS-5 for trauma, the ASEBA, and the K-SADS for affective and Schizophrenia in children. Clinical observation – Clinical psychologists are also trained to gather data by observing behavior. The clinical interview is a vital part of the assessment, even when using other formalized tools, which can employ either a structured or unstructured format. Such assessment looks at certain areas, such as general appearance and behavior, mood and affects, perception, comprehension, orientation, insight, memory, and content of the communication. One psychiatric example of a formal interview is the mental status examination, which is often used in psychiatry as a screening tool for treatment or further testing.
Sources: en.wikipedia.org
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.
No. The peptide is synthetic, although it is modelled on a fragment of a naturally occurring hormone. ACTH(4-10) is generated when ACTH is cleaved, but the Pro-Gly-Pro extension is not a known endogenous sequence. It is therefore a designed analogue rather than a natural metabolite.
The label reflects reported effects on attention, memory and recovery after neurological injury in regional clinical reports. Those reports are mostly small and have not been widely replicated outside the region. The classification is descriptive and does not imply a single defined mechanism.
Each freeze-thaw cycle can degrade a fraction of the peptide and promote aggregation. Dividing a stock solution into single-use volumes removes repeated cycling as a variable. It also limits the time a thawed solution spends at room temperature.